--- /dev/null
+/*
+ * Qualcomm Technologies HIDMA DMA engine low level code
+ *
+ * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/atomic.h>
+#include <linux/iopoll.h>
+#include <linux/kfifo.h>
+#include <linux/bitops.h>
+
+#include "hidma.h"
+
+#define HIDMA_EVRE_SIZE 16 /* each EVRE is 16 bytes */
+
+#define HIDMA_TRCA_CTRLSTS_REG 0x000
+#define HIDMA_TRCA_RING_LOW_REG 0x008
+#define HIDMA_TRCA_RING_HIGH_REG 0x00C
+#define HIDMA_TRCA_RING_LEN_REG 0x010
+#define HIDMA_TRCA_DOORBELL_REG 0x400
+
+#define HIDMA_EVCA_CTRLSTS_REG 0x000
+#define HIDMA_EVCA_INTCTRL_REG 0x004
+#define HIDMA_EVCA_RING_LOW_REG 0x008
+#define HIDMA_EVCA_RING_HIGH_REG 0x00C
+#define HIDMA_EVCA_RING_LEN_REG 0x010
+#define HIDMA_EVCA_WRITE_PTR_REG 0x020
+#define HIDMA_EVCA_DOORBELL_REG 0x400
+
+#define HIDMA_EVCA_IRQ_STAT_REG 0x100
+#define HIDMA_EVCA_IRQ_CLR_REG 0x108
+#define HIDMA_EVCA_IRQ_EN_REG 0x110
+
+#define HIDMA_EVRE_CFG_IDX 0
+
+#define HIDMA_EVRE_ERRINFO_BIT_POS 24
+#define HIDMA_EVRE_CODE_BIT_POS 28
+
+#define HIDMA_EVRE_ERRINFO_MASK GENMASK(3, 0)
+#define HIDMA_EVRE_CODE_MASK GENMASK(3, 0)
+
+#define HIDMA_CH_CONTROL_MASK GENMASK(7, 0)
+#define HIDMA_CH_STATE_MASK GENMASK(7, 0)
+#define HIDMA_CH_STATE_BIT_POS 0x8
+
+#define HIDMA_IRQ_EV_CH_EOB_IRQ_BIT_POS 0
+#define HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS 1
+#define HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS 9
+#define HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS 10
+#define HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS 11
+#define HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS 14
+
+#define ENABLE_IRQS (BIT(HIDMA_IRQ_EV_CH_EOB_IRQ_BIT_POS) | \
+ BIT(HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS))
+
+#define HIDMA_INCREMENT_ITERATOR(iter, size, ring_size) \
+do { \
+ iter += size; \
+ if (iter >= ring_size) \
+ iter -= ring_size; \
+} while (0)
+
+#define HIDMA_CH_STATE(val) \
+ ((val >> HIDMA_CH_STATE_BIT_POS) & HIDMA_CH_STATE_MASK)
+
+#define HIDMA_ERR_INT_MASK \
+ (BIT(HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS) | \
+ BIT(HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS) | \
+ BIT(HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS))
+
+enum ch_command {
+ HIDMA_CH_DISABLE = 0,
+ HIDMA_CH_ENABLE = 1,
+ HIDMA_CH_SUSPEND = 2,
+ HIDMA_CH_RESET = 9,
+};
+
+enum ch_state {
+ HIDMA_CH_DISABLED = 0,
+ HIDMA_CH_ENABLED = 1,
+ HIDMA_CH_RUNNING = 2,
+ HIDMA_CH_SUSPENDED = 3,
+ HIDMA_CH_STOPPED = 4,
+};
+
+enum tre_type {
+ HIDMA_TRE_MEMCPY = 3,
+};
+
+enum err_code {
+ HIDMA_EVRE_STATUS_COMPLETE = 1,
+ HIDMA_EVRE_STATUS_ERROR = 4,
+};
+
+static int hidma_is_chan_enabled(int state)
+{
+ switch (state) {
+ case HIDMA_CH_ENABLED:
+ case HIDMA_CH_RUNNING:
+ return true;
+ default:
+ return false;
+ }
+}
+
+void hidma_ll_free(struct hidma_lldev *lldev, u32 tre_ch)
+{
+ struct hidma_tre *tre;
+
+ if (tre_ch >= lldev->nr_tres) {
+ dev_err(lldev->dev, "invalid TRE number in free:%d", tre_ch);
+ return;
+ }
+
+ tre = &lldev->trepool[tre_ch];
+ if (atomic_read(&tre->allocated) != true) {
+ dev_err(lldev->dev, "trying to free an unused TRE:%d", tre_ch);
+ return;
+ }
+
+ atomic_set(&tre->allocated, 0);
+}
+
+int hidma_ll_request(struct hidma_lldev *lldev, u32 sig, const char *dev_name,
+ void (*callback)(void *data), void *data, u32 *tre_ch)
+{
+ unsigned int i;
+ struct hidma_tre *tre;
+ u32 *tre_local;
+
+ if (!tre_ch || !lldev)
+ return -EINVAL;
+
+ /* need to have at least one empty spot in the queue */
+ for (i = 0; i < lldev->nr_tres - 1; i++) {
+ if (atomic_add_unless(&lldev->trepool[i].allocated, 1, 1))
+ break;
+ }
+
+ if (i == (lldev->nr_tres - 1))
+ return -ENOMEM;
+
+ tre = &lldev->trepool[i];
+ tre->dma_sig = sig;
+ tre->dev_name = dev_name;
+ tre->callback = callback;
+ tre->data = data;
+ tre->idx = i;
+ tre->status = 0;
+ tre->queued = 0;
+ tre->err_code = 0;
+ tre->err_info = 0;
+ tre->lldev = lldev;
+ tre_local = &tre->tre_local[0];
+ tre_local[HIDMA_TRE_CFG_IDX] = HIDMA_TRE_MEMCPY;
+ tre_local[HIDMA_TRE_CFG_IDX] |= (lldev->chidx & 0xFF) << 8;
+ tre_local[HIDMA_TRE_CFG_IDX] |= BIT(16); /* set IEOB */
+ *tre_ch = i;
+ if (callback)
+ callback(data);
+ return 0;
+}
+
+/*
+ * Multiple TREs may be queued and waiting in the pending queue.
+ */
+static void hidma_ll_tre_complete(unsigned long arg)
+{
+ struct hidma_lldev *lldev = (struct hidma_lldev *)arg;
+ struct hidma_tre *tre;
+
+ while (kfifo_out(&lldev->handoff_fifo, &tre, 1)) {
+ /* call the user if it has been read by the hardware */
+ if (tre->callback)
+ tre->callback(tre->data);
+ }
+}
+
+static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
+ u8 err_info, u8 err_code)
+{
+ struct hidma_tre *tre;
+ unsigned long flags;
+
+ spin_lock_irqsave(&lldev->lock, flags);
+ tre = lldev->pending_tre_list[tre_iterator / HIDMA_TRE_SIZE];
+ if (!tre) {
+ spin_unlock_irqrestore(&lldev->lock, flags);
+ dev_warn(lldev->dev, "tre_index [%d] and tre out of sync\n",
+ tre_iterator / HIDMA_TRE_SIZE);
+ return -EINVAL;
+ }
+ lldev->pending_tre_list[tre->tre_index] = NULL;
+
+ /*
+ * Keep track of pending TREs that SW is expecting to receive
+ * from HW. We got one now. Decrement our counter.
+ */
+ lldev->pending_tre_count--;
+ if (lldev->pending_tre_count < 0) {
+ dev_warn(lldev->dev, "tre count mismatch on completion");
+ lldev->pending_tre_count = 0;
+ }
+
+ spin_unlock_irqrestore(&lldev->lock, flags);
+
+ tre->err_info = err_info;
+ tre->err_code = err_code;
+ tre->queued = 0;
+
+ kfifo_put(&lldev->handoff_fifo, tre);
+ tasklet_schedule(&lldev->task);
+
+ return 0;
+}
+
+/*
+ * Called to handle the interrupt for the channel.
+ * Return a positive number if TRE or EVRE were consumed on this run.
+ * Return a positive number if there are pending TREs or EVREs.
+ * Return 0 if there is nothing to consume or no pending TREs/EVREs found.
+ */
+static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
+{
+ u32 evre_ring_size = lldev->evre_ring_size;
+ u32 tre_ring_size = lldev->tre_ring_size;
+ u32 err_info, err_code, evre_write_off;
+ u32 tre_iterator, evre_iterator;
+ u32 num_completed = 0;
+
+ evre_write_off = readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
+ tre_iterator = lldev->tre_processed_off;
+ evre_iterator = lldev->evre_processed_off;
+
+ if ((evre_write_off > evre_ring_size) ||
+ (evre_write_off % HIDMA_EVRE_SIZE)) {
+ dev_err(lldev->dev, "HW reports invalid EVRE write offset\n");
+ return 0;
+ }
+
+ /*
+ * By the time control reaches here the number of EVREs and TREs
+ * may not match. Only consume the ones that hardware told us.
+ */
+ while ((evre_iterator != evre_write_off)) {
+ u32 *current_evre = lldev->evre_ring + evre_iterator;
+ u32 cfg;
+
+ cfg = current_evre[HIDMA_EVRE_CFG_IDX];
+ err_info = cfg >> HIDMA_EVRE_ERRINFO_BIT_POS;
+ err_info &= HIDMA_EVRE_ERRINFO_MASK;
+ err_code =
+ (cfg >> HIDMA_EVRE_CODE_BIT_POS) & HIDMA_EVRE_CODE_MASK;
+
+ if (hidma_post_completed(lldev, tre_iterator, err_info,
+ err_code))
+ break;
+
+ HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
+ tre_ring_size);
+ HIDMA_INCREMENT_ITERATOR(evre_iterator, HIDMA_EVRE_SIZE,
+ evre_ring_size);
+
+ /*
+ * Read the new event descriptor written by the HW.
+ * As we are processing the delivered events, other events
+ * get queued to the SW for processing.
+ */
+ evre_write_off =
+ readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
+ num_completed++;
+ }
+
+ if (num_completed) {
+ u32 evre_read_off = (lldev->evre_processed_off +
+ HIDMA_EVRE_SIZE * num_completed);
+ u32 tre_read_off = (lldev->tre_processed_off +
+ HIDMA_TRE_SIZE * num_completed);
+
+ evre_read_off = evre_read_off % evre_ring_size;
+ tre_read_off = tre_read_off % tre_ring_size;
+
+ writel(evre_read_off, lldev->evca + HIDMA_EVCA_DOORBELL_REG);
+
+ /* record the last processed tre offset */
+ lldev->tre_processed_off = tre_read_off;
+ lldev->evre_processed_off = evre_read_off;
+ }
+
+ return num_completed;
+}
+
+void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info,
+ u8 err_code)
+{
+ u32 tre_iterator;
+ u32 tre_ring_size = lldev->tre_ring_size;
+ int num_completed = 0;
+ u32 tre_read_off;
+
+ tre_iterator = lldev->tre_processed_off;
+ while (lldev->pending_tre_count) {
+ if (hidma_post_completed(lldev, tre_iterator, err_info,
+ err_code))
+ break;
+ HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
+ tre_ring_size);
+ num_completed++;
+ }
+ tre_read_off = (lldev->tre_processed_off +
+ HIDMA_TRE_SIZE * num_completed);
+
+ tre_read_off = tre_read_off % tre_ring_size;
+
+ /* record the last processed tre offset */
+ lldev->tre_processed_off = tre_read_off;
+}
+
+static int hidma_ll_reset(struct hidma_lldev *lldev)
+{
+ u32 val;
+ int ret;
+
+ val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+ val &= ~(HIDMA_CH_CONTROL_MASK << 16);
+ val |= HIDMA_CH_RESET << 16;
+ writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+
+ /*
+ * Delay 10ms after reset to allow DMA logic to quiesce.
+ * Do a polled read up to 1ms and 10ms maximum.
+ */
+ ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val,
+ HIDMA_CH_STATE(val) == HIDMA_CH_DISABLED,
+ 1000, 10000);
+ if (ret) {
+ dev_err(lldev->dev, "transfer channel did not reset\n");
+ return ret;
+ }
+
+ val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+ val &= ~(HIDMA_CH_CONTROL_MASK << 16);
+ val |= HIDMA_CH_RESET << 16;
+ writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+
+ /*
+ * Delay 10ms after reset to allow DMA logic to quiesce.
+ * Do a polled read up to 1ms and 10ms maximum.
+ */
+ ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val,
+ HIDMA_CH_STATE(val) == HIDMA_CH_DISABLED,
+ 1000, 10000);
+ if (ret)
+ return ret;
+
+ lldev->trch_state = HIDMA_CH_DISABLED;
+ lldev->evch_state = HIDMA_CH_DISABLED;
+ return 0;
+}
+
+/*
+ * Abort all transactions and perform a reset.
+ */
+static void hidma_ll_abort(unsigned long arg)
+{
+ struct hidma_lldev *lldev = (struct hidma_lldev *)arg;
+ u8 err_code = HIDMA_EVRE_STATUS_ERROR;
+ u8 err_info = 0xFF;
+ int rc;
+
+ hidma_cleanup_pending_tre(lldev, err_info, err_code);
+
+ /* reset the channel for recovery */
+ rc = hidma_ll_setup(lldev);
+ if (rc) {
+ dev_err(lldev->dev, "channel reinitialize failed after error\n");
+ return;
+ }
+ writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+}
+
+/*
+ * The interrupt handler for HIDMA will try to consume as many pending
+ * EVRE from the event queue as possible. Each EVRE has an associated
+ * TRE that holds the user interface parameters. EVRE reports the
+ * result of the transaction. Hardware guarantees ordering between EVREs
+ * and TREs. We use last processed offset to figure out which TRE is
+ * associated with which EVRE. If two TREs are consumed by HW, the EVREs
+ * are in order in the event ring.
+ *
+ * This handler will do a one pass for consuming EVREs. Other EVREs may
+ * be delivered while we are working. It will try to consume incoming
+ * EVREs one more time and return.
+ *
+ * For unprocessed EVREs, hardware will trigger another interrupt until
+ * all the interrupt bits are cleared.
+ *
+ * Hardware guarantees that by the time interrupt is observed, all data
+ * transactions in flight are delivered to their respective places and
+ * are visible to the CPU.
+ *
+ * On demand paging for IOMMU is only supported for PCIe via PRI
+ * (Page Request Interface) not for HIDMA. All other hardware instances
+ * including HIDMA work on pinned DMA addresses.
+ *
+ * HIDMA is not aware of IOMMU presence since it follows the DMA API. All
+ * IOMMU latency will be built into the data movement time. By the time
+ * interrupt happens, IOMMU lookups + data movement has already taken place.
+ *
+ * While the first read in a typical PCI endpoint ISR flushes all outstanding
+ * requests traditionally to the destination, this concept does not apply
+ * here for this HW.
+ */
+irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
+{
+ struct hidma_lldev *lldev = arg;
+ u32 status;
+ u32 enable;
+ u32 cause;
+
+ /*
+ * Fine tuned for this HW...
+ *
+ * This ISR has been designed for this particular hardware. Relaxed
+ * read and write accessors are used for performance reasons due to
+ * interrupt delivery guarantees. Do not copy this code blindly and
+ * expect that to work.
+ */
+ status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
+ enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+ cause = status & enable;
+
+ while (cause) {
+ if (cause & HIDMA_ERR_INT_MASK) {
+ dev_err(lldev->dev, "error 0x%x, resetting...\n",
+ cause);
+
+ /* Clear out pending interrupts */
+ writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+
+ tasklet_schedule(&lldev->rst_task);
+ goto out;
+ }
+
+ /*
+ * Try to consume as many EVREs as possible.
+ */
+ hidma_handle_tre_completion(lldev);
+
+ /* We consumed TREs or there are pending TREs or EVREs. */
+ writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+
+ /*
+ * Another interrupt might have arrived while we are
+ * processing this one. Read the new cause.
+ */
+ status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
+ enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+ cause = status & enable;
+ }
+
+out:
+ return IRQ_HANDLED;
+}
+
+int hidma_ll_enable(struct hidma_lldev *lldev)
+{
+ u32 val;
+ int ret;
+
+ val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+ val &= ~(HIDMA_CH_CONTROL_MASK << 16);
+ val |= HIDMA_CH_ENABLE << 16;
+ writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+
+ ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val,
+ hidma_is_chan_enabled(HIDMA_CH_STATE(val)),
+ 1000, 10000);
+ if (ret) {
+ dev_err(lldev->dev, "event channel did not get enabled\n");
+ return ret;
+ }
+
+ val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+ val &= ~(HIDMA_CH_CONTROL_MASK << 16);
+ val |= HIDMA_CH_ENABLE << 16;
+ writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+
+ ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val,
+ hidma_is_chan_enabled(HIDMA_CH_STATE(val)),
+ 1000, 10000);
+ if (ret) {
+ dev_err(lldev->dev, "transfer channel did not get enabled\n");
+ return ret;
+ }
+
+ lldev->trch_state = HIDMA_CH_ENABLED;
+ lldev->evch_state = HIDMA_CH_ENABLED;
+
+ return 0;
+}
+
+void hidma_ll_start(struct hidma_lldev *lldev)
+{
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&lldev->lock, irqflags);
+ writel(lldev->tre_write_offset, lldev->trca + HIDMA_TRCA_DOORBELL_REG);
+ spin_unlock_irqrestore(&lldev->lock, irqflags);
+}
+
+bool hidma_ll_isenabled(struct hidma_lldev *lldev)
+{
+ u32 val;
+
+ val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+ lldev->trch_state = HIDMA_CH_STATE(val);
+ val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+ lldev->evch_state = HIDMA_CH_STATE(val);
+
+ /* both channels have to be enabled before calling this function */
+ if (hidma_is_chan_enabled(lldev->trch_state) &&
+ hidma_is_chan_enabled(lldev->evch_state))
+ return true;
+
+ return false;
+}
+
+void hidma_ll_queue_request(struct hidma_lldev *lldev, u32 tre_ch)
+{
+ struct hidma_tre *tre;
+ unsigned long flags;
+
+ tre = &lldev->trepool[tre_ch];
+
+ /* copy the TRE into its location in the TRE ring */
+ spin_lock_irqsave(&lldev->lock, flags);
+ tre->tre_index = lldev->tre_write_offset / HIDMA_TRE_SIZE;
+ lldev->pending_tre_list[tre->tre_index] = tre;
+ memcpy(lldev->tre_ring + lldev->tre_write_offset,
+ &tre->tre_local[0], HIDMA_TRE_SIZE);
+ tre->err_code = 0;
+ tre->err_info = 0;
+ tre->queued = 1;
+ lldev->pending_tre_count++;
+ lldev->tre_write_offset = (lldev->tre_write_offset + HIDMA_TRE_SIZE)
+ % lldev->tre_ring_size;
+ spin_unlock_irqrestore(&lldev->lock, flags);
+}
+
+/*
+ * Note that even though we stop this channel if there is a pending transaction
+ * in flight it will complete and follow the callback. This request will
+ * prevent further requests to be made.
+ */
+int hidma_ll_disable(struct hidma_lldev *lldev)
+{
+ u32 val;
+ int ret;
+
+ val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+ lldev->evch_state = HIDMA_CH_STATE(val);
+ val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+ lldev->trch_state = HIDMA_CH_STATE(val);
+
+ /* already suspended by this OS */
+ if ((lldev->trch_state == HIDMA_CH_SUSPENDED) ||
+ (lldev->evch_state == HIDMA_CH_SUSPENDED))
+ return 0;
+
+ /* already stopped by the manager */
+ if ((lldev->trch_state == HIDMA_CH_STOPPED) ||
+ (lldev->evch_state == HIDMA_CH_STOPPED))
+ return 0;
+
+ val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+ val &= ~(HIDMA_CH_CONTROL_MASK << 16);
+ val |= HIDMA_CH_SUSPEND << 16;
+ writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
+
+ /*
+ * Start the wait right after the suspend is confirmed.
+ * Do a polled read up to 1ms and 10ms maximum.
+ */
+ ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val,
+ HIDMA_CH_STATE(val) == HIDMA_CH_SUSPENDED,
+ 1000, 10000);
+ if (ret)
+ return ret;
+
+ val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+ val &= ~(HIDMA_CH_CONTROL_MASK << 16);
+ val |= HIDMA_CH_SUSPEND << 16;
+ writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+
+ /*
+ * Start the wait right after the suspend is confirmed
+ * Delay up to 10ms after reset to allow DMA logic to quiesce.
+ */
+ ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val,
+ HIDMA_CH_STATE(val) == HIDMA_CH_SUSPENDED,
+ 1000, 10000);
+ if (ret)
+ return ret;
+
+ lldev->trch_state = HIDMA_CH_SUSPENDED;
+ lldev->evch_state = HIDMA_CH_SUSPENDED;
+ return 0;
+}
+
+void hidma_ll_set_transfer_params(struct hidma_lldev *lldev, u32 tre_ch,
+ dma_addr_t src, dma_addr_t dest, u32 len,
+ u32 flags)
+{
+ struct hidma_tre *tre;
+ u32 *tre_local;
+
+ if (tre_ch >= lldev->nr_tres) {
+ dev_err(lldev->dev, "invalid TRE number in transfer params:%d",
+ tre_ch);
+ return;
+ }
+
+ tre = &lldev->trepool[tre_ch];
+ if (atomic_read(&tre->allocated) != true) {
+ dev_err(lldev->dev, "trying to set params on an unused TRE:%d",
+ tre_ch);
+ return;
+ }
+
+ tre_local = &tre->tre_local[0];
+ tre_local[HIDMA_TRE_LEN_IDX] = len;
+ tre_local[HIDMA_TRE_SRC_LOW_IDX] = lower_32_bits(src);
+ tre_local[HIDMA_TRE_SRC_HI_IDX] = upper_32_bits(src);
+ tre_local[HIDMA_TRE_DEST_LOW_IDX] = lower_32_bits(dest);
+ tre_local[HIDMA_TRE_DEST_HI_IDX] = upper_32_bits(dest);
+ tre->int_flags = flags;
+}
+
+/*
+ * Called during initialization and after an error condition
+ * to restore hardware state.
+ */
+int hidma_ll_setup(struct hidma_lldev *lldev)
+{
+ int rc;
+ u64 addr;
+ u32 val;
+ u32 nr_tres = lldev->nr_tres;
+
+ lldev->pending_tre_count = 0;
+ lldev->tre_processed_off = 0;
+ lldev->evre_processed_off = 0;
+ lldev->tre_write_offset = 0;
+
+ /* disable interrupts */
+ writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+
+ /* clear all pending interrupts */
+ val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
+ writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+
+ rc = hidma_ll_reset(lldev);
+ if (rc)
+ return rc;
+
+ /*
+ * Clear all pending interrupts again.
+ * Otherwise, we observe reset complete interrupts.
+ */
+ val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
+ writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+
+ /* disable interrupts again after reset */
+ writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+
+ addr = lldev->tre_dma;
+ writel(lower_32_bits(addr), lldev->trca + HIDMA_TRCA_RING_LOW_REG);
+ writel(upper_32_bits(addr), lldev->trca + HIDMA_TRCA_RING_HIGH_REG);
+ writel(lldev->tre_ring_size, lldev->trca + HIDMA_TRCA_RING_LEN_REG);
+
+ addr = lldev->evre_dma;
+ writel(lower_32_bits(addr), lldev->evca + HIDMA_EVCA_RING_LOW_REG);
+ writel(upper_32_bits(addr), lldev->evca + HIDMA_EVCA_RING_HIGH_REG);
+ writel(HIDMA_EVRE_SIZE * nr_tres,
+ lldev->evca + HIDMA_EVCA_RING_LEN_REG);
+
+ /* support IRQ only for now */
+ val = readl(lldev->evca + HIDMA_EVCA_INTCTRL_REG);
+ val &= ~0xF;
+ val |= 0x1;
+ writel(val, lldev->evca + HIDMA_EVCA_INTCTRL_REG);
+
+ /* clear all pending interrupts and enable them */
+ writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+ writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+
+ return hidma_ll_enable(lldev);
+}
+
+struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres,
+ void __iomem *trca, void __iomem *evca,
+ u8 chidx)
+{
+ u32 required_bytes;
+ struct hidma_lldev *lldev;
+ int rc;
+ size_t sz;
+
+ if (!trca || !evca || !dev || !nr_tres)
+ return NULL;
+
+ /* need at least four TREs */
+ if (nr_tres < 4)
+ return NULL;
+
+ /* need an extra space */
+ nr_tres += 1;
+
+ lldev = devm_kzalloc(dev, sizeof(struct hidma_lldev), GFP_KERNEL);
+ if (!lldev)
+ return NULL;
+
+ lldev->evca = evca;
+ lldev->trca = trca;
+ lldev->dev = dev;
+ sz = sizeof(struct hidma_tre);
+ lldev->trepool = devm_kcalloc(lldev->dev, nr_tres, sz, GFP_KERNEL);
+ if (!lldev->trepool)
+ return NULL;
+
+ required_bytes = sizeof(lldev->pending_tre_list[0]);
+ lldev->pending_tre_list = devm_kcalloc(dev, nr_tres, required_bytes,
+ GFP_KERNEL);
+ if (!lldev->pending_tre_list)
+ return NULL;
+
+ sz = (HIDMA_TRE_SIZE + 1) * nr_tres;
+ lldev->tre_ring = dmam_alloc_coherent(dev, sz, &lldev->tre_dma,
+ GFP_KERNEL);
+ if (!lldev->tre_ring)
+ return NULL;
+
+ memset(lldev->tre_ring, 0, (HIDMA_TRE_SIZE + 1) * nr_tres);
+ lldev->tre_ring_size = HIDMA_TRE_SIZE * nr_tres;
+ lldev->nr_tres = nr_tres;
+
+ /* the TRE ring has to be TRE_SIZE aligned */
+ if (!IS_ALIGNED(lldev->tre_dma, HIDMA_TRE_SIZE)) {
+ u8 tre_ring_shift;
+
+ tre_ring_shift = lldev->tre_dma % HIDMA_TRE_SIZE;
+ tre_ring_shift = HIDMA_TRE_SIZE - tre_ring_shift;
+ lldev->tre_dma += tre_ring_shift;
+ lldev->tre_ring += tre_ring_shift;
+ }
+
+ sz = (HIDMA_EVRE_SIZE + 1) * nr_tres;
+ lldev->evre_ring = dmam_alloc_coherent(dev, sz, &lldev->evre_dma,
+ GFP_KERNEL);
+ if (!lldev->evre_ring)
+ return NULL;
+
+ memset(lldev->evre_ring, 0, (HIDMA_EVRE_SIZE + 1) * nr_tres);
+ lldev->evre_ring_size = HIDMA_EVRE_SIZE * nr_tres;
+
+ /* the EVRE ring has to be EVRE_SIZE aligned */
+ if (!IS_ALIGNED(lldev->evre_dma, HIDMA_EVRE_SIZE)) {
+ u8 evre_ring_shift;
+
+ evre_ring_shift = lldev->evre_dma % HIDMA_EVRE_SIZE;
+ evre_ring_shift = HIDMA_EVRE_SIZE - evre_ring_shift;
+ lldev->evre_dma += evre_ring_shift;
+ lldev->evre_ring += evre_ring_shift;
+ }
+ lldev->nr_tres = nr_tres;
+ lldev->chidx = chidx;
+
+ sz = nr_tres * sizeof(struct hidma_tre *);
+ rc = kfifo_alloc(&lldev->handoff_fifo, sz, GFP_KERNEL);
+ if (rc)
+ return NULL;
+
+ rc = hidma_ll_setup(lldev);
+ if (rc)
+ return NULL;
+
+ spin_lock_init(&lldev->lock);
+ tasklet_init(&lldev->rst_task, hidma_ll_abort, (unsigned long)lldev);
+ tasklet_init(&lldev->task, hidma_ll_tre_complete, (unsigned long)lldev);
+ lldev->initialized = 1;
+ writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+ return lldev;
+}
+
+int hidma_ll_uninit(struct hidma_lldev *lldev)
+{
+ u32 required_bytes;
+ int rc = 0;
+ u32 val;
+
+ if (!lldev)
+ return -ENODEV;
+
+ if (!lldev->initialized)
+ return 0;
+
+ lldev->initialized = 0;
+
+ required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres;
+ tasklet_kill(&lldev->task);
+ memset(lldev->trepool, 0, required_bytes);
+ lldev->trepool = NULL;
+ lldev->pending_tre_count = 0;
+ lldev->tre_write_offset = 0;
+
+ rc = hidma_ll_reset(lldev);
+
+ /*
+ * Clear all pending interrupts again.
+ * Otherwise, we observe reset complete interrupts.
+ */
+ val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
+ writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+ writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+ return rc;
+}
+
+enum dma_status hidma_ll_status(struct hidma_lldev *lldev, u32 tre_ch)
+{
+ enum dma_status ret = DMA_ERROR;
+ struct hidma_tre *tre;
+ unsigned long flags;
+ u8 err_code;
+
+ spin_lock_irqsave(&lldev->lock, flags);
+
+ tre = &lldev->trepool[tre_ch];
+ err_code = tre->err_code;
+
+ if (err_code & HIDMA_EVRE_STATUS_COMPLETE)
+ ret = DMA_COMPLETE;
+ else if (err_code & HIDMA_EVRE_STATUS_ERROR)
+ ret = DMA_ERROR;
+ else
+ ret = DMA_IN_PROGRESS;
+ spin_unlock_irqrestore(&lldev->lock, flags);
+
+ return ret;
+}
projects / linux-2.6-microblaze.git / commitdiff